<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        div {
            /* 1.设置边框的粗细 */
            border-width: 3px;
            /* 2.设置边框的颜色 */
            border-color: blue;
            /* 3.设置边框的样式 实线solid 虚线dashed 点线dotted */
            border-style: solid;
            border-style: dashed;
            border-style: dotted;
            /*  */
            border: 3px solid palevioletred;

        }
    </style>
</head>

<body>
    <div>1</div>
</body>

</html>